Very good cast for whenever:

In your Rails applications you’ll often need to handle recurring processes or tasks, be it rolling log files once an hour, restarting a daemon once a week or clearing out old cache files. The most common way of doing this is to use cron , which is available on most UNIX-based systems. Say you want to run a rake task under cron every morning. You’d start by editing a new crontab file by running crontab -e which would bring up an empty crontab file for editing. Unless you’re familiar with the syntax for crontab you’ll probably start reaching for the manuals about now as it can be a little tricky to remember. For example, if you wanted to run a command at 2.30 every morning you’d have to enter something like 30 2 * * * cd /Users/eifion/rails/myrailsapp && execute_some_command and then test it to make sure you’d got the syntax correct. Another problem with using crontab is tha...